JP2002047329A - Aromatic polyester polyol and polyurethane resin using the polyol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a new aromatic polyester polyol for urethane resins having a high mechanical property and low resilience, using a polyalkylene phthalate resin as a raw material, and to enable a chemical recycle of the polyalkylene phthalate resins. SOLUTION: This aromatic polyester polyol for polyurethane resins is obtained by reacting polyalkylene phthalate resins with glycols, which a hydroxyl value is 20 or 100 mgKOH/g, an acid value is <=0.4 mgKOH/g, the metal content is <=100 μg/g, the content ratio of a COO-C6H4-COO unit in the aromatic polyester polyol is >=2 mass% and <=65 mass%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aromatic polyester polyol useful as a raw material for a polyurethane resin and a method for producing the aromatic polyester polyol. Further, in the method for producing an aromatic polyester polyol of the present invention, as the raw material polyalkylene phthalate, recovered and regenerated polyalkylene phthalate or a waste product generated in the production or processing step of the polyalkylene phthalate can be used. The present invention relates to a method for producing an aromatic polyester polyol. Further, the present invention relates to a urethane resin using the aromatic polyester polyol.

[0002]

2. Description of the Related Art Polyurethane resins have excellent physical properties,
Due to productivity, it is widely used in automobiles, building materials, home appliances, bedding, furniture, clothing, footwear, heat insulating materials, paints, and the like. Of these, cushions such as automobiles and furniture, which are in the field of direct contact with humans, footwear, and the like, are desired to be reduced in weight from the viewpoint of energy saving and low cost. In order to reduce the weight, it is necessary to reduce the density.However, when the density is reduced, mechanical properties such as tensile strength are reduced, and not only physical properties required as a product are not exhibited, but also the cost is increased due to reduced productivity. There is a disadvantage that it becomes.

In order to reduce the weight and not to decrease the physical properties, it is necessary to increase the mechanical physical properties of polyurethane.
In order to solve this problem, an attempt to improve physical properties by using low monol polypropylene glycol (see JP-A-3-45618 and JP-A-3-68618) is disclosed. As a result, mechanical properties such as tensile strength could be improved.
There is a demand for further improvement in low resilience having high performance of absorbing shock and vibration, which is further required for microcellular and elastomer such as cushions for furniture, footwear and the like.

On the other hand, in recent years, there has been a demand for resin recycling, and a chemical recycling technology such as polyethylene terephthalate has been required. As one of recycling methods, a method of producing a terephthalate-based polyol by a transesterification reaction using a polyhydric alcohol (Japanese Unexamined Patent Publication No.
-10,024, JP-A-60-130620)
However, the production of a polyol having a low molecular weight and no turbidity or precipitation for a rigid polyurethane has been limited, and further improvement in performance as an aromatic polyester polyol has been desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polyester polyol having high mechanical properties and capable of producing a polyurethane resin having low rebound resilience. It is another object of the present invention to provide a method for producing an aromatic polyester polyol, which can also use, as a raw material, recovered or regenerated polyalkylene phthalate, or waste generated in a polyalkylene phthalate production step or a processing step. .

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have used an aromatic polyester polyol having a specific hydroxyl value and an acid value, which is produced from a specific raw material. As a result, they have found that a polyurethane resin having high mechanical strength and low rebound resilience can be produced, and the present invention has been completed.

That is, the present invention provides the following (1) to (6). (1) Polyalkylene phthalate resin and glycol
And 1) a hydroxyl value of 20 to 100 mg KOH / g, 2) an acid value of 0.4 mg KOH / g or less, 3) a metal content of 100 μg / g or less, _{4) COO-C 6 H 4} -COO content of the aromatic polyester polyol of the unit at least 2 wt% 65 wt% or less, aromatic ester polyol for the polyurethane resin is. (2) 5) The viscosity measured at 60 ° C. is 200 m
The aromatic polyester polyol according to (1), wherein the aromatic polyester polyol is in a range from Pa · s to 50,000 mPa · s. (3) The aromatic polyester polyol according to any one of (1) and (2), obtained using a glycol having a water content of 0.3% by mass or less. (4) Weight average molecular weight of 20,000 to 80000
Having a number average molecular weight of 8,000 to 3,000.
The aromatic polyester polyol according to any one of (1) and (2), which is obtained by using a polyalkylene phthalate having a water content of 0.5% by mass or less in a range of 0. (5) When producing an aromatic polyester polyol from a polyalkylene phthalate and a glycol, the aromatic polyester according to any one of (1) to (4) is subjected to azeotropic dehydration using a solvent azeotropic with water in the presence of glycol. A method for producing a polyester polyol. (6) A polyurethane resin obtained by reacting the aromatic polyester polyol described in (1) or (2) with polyisocyanate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the aromatic polyester polyol of the present invention, a method for producing the aromatic polyester polyol (hereinafter, referred to as "the method of the present invention"), and a polyurethane resin produced using the aromatic ester polyol Will be described in more detail.

[0009] It [aromatic polyester polyol] and aromatic polyester polyols of the present invention may be obtained by reacting a glycol polyalkylene phthalate resin 1) hydroxyl value of 20 to 100 mg KOH / g, 2) acid value 0 3) a metal content of 100 μg / g or less, 4) a fragrance having a COO—C ₆ H ₄ —COO unit content in the aromatic polyester polyol of 2% by mass or more and 65% by mass or less. It is an aromatic ester polyol. The aromatic polyol is mainly composed of an ester skeleton obtained by dehydration-condensation of a dicarboxylic acid having a phthalic acid skeleton and a glycol compound, and optionally contains other components in its molecule. Is also good. The hydroxyl value is usually 20 mgK
OH / g or more and 100 mgKOH / g or less, preferably 30 mgKOH / g or more and 100 mgKOH.
Further, the acid value is 0.4 mgKOH / g or less, preferably 0.2 mgKOH / g or less. Further, the concentration of the metal component contained in the aromatic polyester polyol,
It is 100 μg / g or less, preferably 50 μg / g or less. In particular, when at least one of antimony and germanium is contained in the metal component, the content is 60 μg.
/ G or less, particularly preferably 30 μg / g or less. COO-C ₆ H ₄ content in the aromatic polyester polyol -COO units than 2 wt% 65 wt% or less,
Preferably it is 10 mass% or more and 60 mass% or less. Since COO-C ₆ H ₄ -COO unit of the present invention has substantially all the ester bonds, hereinafter referred to as aromatic ester content. When the aromatic ester content is 2% by mass or more, mechanical properties can be improved, and when the aromatic ester content is 65% by mass or less, the viscosity of the aromatic polyester polyol can be kept low, and the aromatic polyester polyol is produced. In addition to the above, it is preferable because the viscosity of a resin premix or the like using an aromatic polyester polyol can be reduced. Although the viscosity of the aromatic polyester polyol of the present invention is not particularly limited, the viscosity measured at 60 ° C. is 200 mPa · s or more and 50,000 mPa.
・ It is desirable to be in the range of s or less.

[Method for Producing Aromatic Polyester Polyol] The aromatic polyester polyol of the present invention can be produced by reacting a polyalkylene phthalate resin with glycol in the presence of a catalyst for transesterification. Water and glycol by-produced in the above reaction (that is, glycol forming the polyalkylene terephthalate resin as a raw material) can be removed as necessary. Needless to say, removal and purification of impurities such as antimony and germanium may be performed as necessary.

(Polyalkylene phthalate resin) The polyalkylene phthalate resin used as a raw material in the method of the present invention may be any resin produced using phthalic acid, and may be produced for producing the present aromatic polyester polyol. Even if the resin is used for another purpose, a recovered polyalkylene phthalate resin obtained after diversion or use of a product manufactured for another purpose may be used. In addition to terephthalic acid, a raw material of the polyalkylene phthalate may be one produced solely or in combination of two or more isomers of phthalic acid such as orthophthalic acid and terephthalic acid. Less than,
The polyalkylene terephthalate, which is the easiest to obtain, will be described as a representative. In addition to virgin resin (resin manufactured as a product from terephthalic acid and alkylene glycol and not having undergone a recycling process), waste generated in the manufacturing or processing of polyalkylene terephthalate, or other uses such as bottles and films After being used for the above, those that have been recovered and regenerated can be used. The polyalkylene terephthalate waste or regenerated one may be in any form, but it is preferable to use flakes or pellets. In particular, for polyethylene terephthalate, a recovery and recycling system for beverage bottles has been established, and recycled products can be obtained as commercial products in the form of flakes or pellets. The water content of these polyalkylene terephthalate resins used in the method of the present invention is usually preferably 0.5% by mass or less, more preferably 0.4% by mass or less. By controlling the water content of the raw material polyalkylene terephthalate resin in this way, it is possible to control the increase in the acid value of the aromatic polyester polyol obtained.

(Glycol) The glycol used as a raw material in the method of the present invention is represented by the following general formula (1):

Embedded image [Wherein, R represents hydrogen or an alkyl group composed of 1 to 5 carbon atoms, 1 represents an integer of 0 or more, and m represents an integer of 1 or more]. There is no particular limitation on l and m in the formula, but preferably l is 1 or more and 7 or less, and m is 1 or more and 90 or less. As specific examples, diethylene glycol, triethylene glycol,
Tetramethylene glycol, pentaethylene glycol, hexaethylene glycol, 1,2-propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, 1,3-propylene glycol, di1.3 -Propylene glycol, tri 1,3-propylene glycol, tetra 1,3
-Propylene glycol, hexamethylene glycol,
Pentamethylene glycol, 3-methyl-1,5-pentanediol, 1,6-hexamethylene glycol, 1,8
-Octamethylene glycol, and oligomers having a molecular weight of 150 to 4000, which are condensates of these glycols. These can be used alone or as a mixture containing two or more. The amount of the raw material glycol used is the viscosity of the aromatic polyester polyol,
It can be appropriately determined according to the hydroxyl value and the performance required for the polyurethane resin. The water content of these raw material glycols used in the method of the present invention is usually preferably 0.3% by mass or less, more preferably 0.2% by mass or less. By controlling the amount of water in the raw material glycol in this manner, the acid value of the obtained aromatic polyester polyol can be suppressed.

(Transesterification Catalyst) In the method of the present invention, the catalyst used in the transesterification reaction between the polyalkylene terephthalate and the starting glycol is not particularly limited, and a catalyst usually used in the transesterification reaction can be used. Examples thereof include Lewis acids, carboxylate salts of alkali metals and alkaline earth metals, protonic acids, activated clay, acidic clay, and ion exchange resins. More specifically, tetrabutoxytitanate,
Dibutyltin oxide, manganese acetate, cobalt acetate, zinc acetate, zinc benzoate, lithium acetate, sodium acetate, magnesium acetate, calcium acetate, acid value antimony, acid value germanium, phosphoric acid, boric acid, sulfuric acid, p-toluenesulfonic acid, Metasulfonic acid, Amberlyst E1
5 and the like. These catalysts are used in an amount of 10 to 500 to the starting polyalkylene terephthalate.
0 μg, preferably 50 to 1000 μg.

(Conversion Conditions for Transesterification) In the process of the present invention, the reaction temperature for the transesterification between the polyalkylene terephthalate and the raw material glycol is usually in the range of 150 to 300 ° C., preferably 200 to 250 ° C. Range. The pressure can be any,
Usually, it is from normal pressure to 1 MPa. The reaction time of the transesterification reaction is not particularly limited, but is usually in the range of 0.5 to 5 hours. The transesterification reaction may be performed by any of batch, semi-batch, and continuous methods.
The glycol component by-produced in the transesterification reaction (that is, the glycol forming the polyalkylene terephthalate resin as the raw material) is distilled off as necessary. This makes it possible to control the hydroxyl value and viscosity of the aromatic polyester polyol within a predetermined range. Although there is no particular limitation on the distillation of the glycol component, it is usually carried out under heating and reduced pressure, or the glycol component is distilled off while reacting in the presence of a transesterification reaction catalyst.
It may be distilled off after the completion of the reaction, but it is preferable to distill it off during the reaction because the ratio of the phthalic acid component and the glycol component at the time of the reaction can be controlled. The temperature of the glycol distillation is usually in the range of 150 to 300 ° C, preferably 20 to 300 ° C.
It is in the range of 0 to 250 ° C. The pressure is usually 0.5 to 0.0001 MPa, preferably 0.1 to 0.0
It is performed in the range of 01 MPa.

(Post-Treatment of Aromatic Polyester Polyol) The obtained aromatic polyester polyol may be used as it is for a polyurethane resin, but impurities such as metals may be removed. In particular, when the content of metals such as antimony and germanium exceeds the above range, it is necessary to perform treatment using an adsorbent or the like. In addition, it goes without saying that the adsorption removal may be performed even when the metal components such as antimony and germanium in the obtained aromatic polyester polyol are within the above range. Furthermore, if the catalyst used for the transesterification remains in the polyol, the hydrolyzability and the thermal stability deteriorate, so it may be removed with an adsorbent, or the catalyst may be hydrolyzed with water such as tetrabutoxytitanate. What decomposes into a compound insoluble in the polyol may be precipitated by hydrolyzing the catalyst by adding water, and then removed by filtration.

[Polyurethane Resin] Polyurethane resin includes flexible polyurethane foam, rigid urethane foam, semi-rigid polyurethane foam, microcellular,
There are various forms such as elastomers and urethane fibers, but industrially, it can be produced by reacting a polyol and polyisocyanate, and if necessary, a chain extender, a catalyst, a foaming agent, and a foam stabilizer. Other auxiliaries such as agents, stabilizers, plasticizers, fillers, and colorants can be added. The polyurethane resin of the present invention is produced by containing the aromatic polyester polyol of the present invention as an essential component.

(Polyisocyanate) The polyisocyanate used in the present invention includes aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, and a modified product obtained by modifying the polyisocyanate with a nullate. Any material such as a mixture of the above-mentioned polyisocyanates may be used as long as it is used for ordinary urethane resins. Examples of the aromatic polyester polyol include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), and tetramethyl xylylene diisocyanate (TMXDI). MDI may be used. As the aliphatic polyisocyanate, isophorone diisocyanate (IPD
I), hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI) and the like. As the alicyclic isocyanate, 2,5
-Diisocyanatomethylbicyclo [2.2.1] heptane, 2,6-diisocyanatomethylbicyclo [2.
2.1] heptane, 3 (4), 8 (9) -di (isocyanatomethyl) tricyclo [5.2.1.0 ^2,6 ] decane (TCDI). In addition, the polyisocyanate may be partially reacted with an active hydrogen compound such as a polyol before reacting with a polyol or other auxiliaries, and used as a modified product (prepolymer). The aromatic polyester polyol of the present invention may be used as a modifier when producing a prepolymer. The amount of conversion by the aromatic polyester polyol of the present invention is 1 to 8 with respect to 100 equivalents of isocyanate groups.
It is 0 hydroxyl equivalent, preferably 10 to 60 hydroxyl equivalent.

(Polyol) If the urethane resin contains the aromatic polyester polyol of the present invention, the effect of the aromatic polyester polyol of the present invention is exhibited. May also be included in the polyol,
It may be contained in both of the denaturing agents, and may not be contained in the polyol but may be contained only as a denaturing agent when producing a prepolymer. The content of the aromatic polyester polyol of the present invention in the polyurethane resin is usually 1 to 80% by mass, preferably 5 to 60% by mass.
It is. For this reason, other polyols described below may be contained.

(Other polyols) As other polyols, known polyols usually used as urethane raw materials can be used. For example, polyether polyol, polyester polyol, polycarbonate polyol and the like can be mentioned.

(Chain extender) As the chain extender, a known chain extender usually used as a urethane raw material can be used.
For example, low molecular glycol, aliphatic amine, aromatic amine and the like can be mentioned.

(Blowing agent) As the blowing agent used in the present invention, known hydrochlorofluorocarbons, hydrocarbons, water and carbon dioxide gas can be used. Further, a mixture of these may be used.

(Catalyst) Examples of the catalyst include amines, aziridines, quaternary ammonium compounds, alkali metal salts, lead compounds, tin compounds, alcoholate compounds, phenolate compounds, metal halide compounds, metal halide compounds, which are usually used in the production of urethane resins. Complex compounds and the like can be used, and a mixture thereof may be used. As amines, trimethylaminoethylpiperazine, triethylamine, tripropylamine, N-methylmorpholine, N-ethylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, dimethylcyclohexylamine, diazobicycloundecene, 1,3,5 -Tris (dimethylaminopropyl) hexahydro-S-ethylaziridine and the like. Examples of the quaternary ammonium compound include carboxylate salts of tertiary amines. Examples of the alkali metal salts include potassium octylate, sodium acetate, and the like. Examples of the lead compound include lead naphthenate and lead octylate. Examples of the tin compound include dibutyltin diacetate and dibutyltin dilaurate.
Examples of the alcoholate compound include sodium methoxide and sodium ethoxide. Examples of the phenolate compound include potassium phenoxide, lithium phenoxide, and sodium phenoxide. Examples of the metal halide include iron chloride, zinc chloride, zinc bromide, tin chloride and the like. Examples of the metal complex compound include a metal complex compound such as a metal salt of acetylacetone. These catalysts can be used alone or in combination of two or more kinds, and the amount of use is suitably 0.001 to 15.0 parts by weight based on 100 parts by weight of the polyol.

(Foam stabilizer) As the foam stabilizer, conventionally known silicon-containing organic surfactants are used. For example, F-327, F-345, F-30 manufactured by Shin-Etsu Chemical Co., Ltd.
5. SZ-1127, SZ-1 manufactured by Nippon Unicar Co., Ltd.
142, SZ-1605, SZ-1642, SZ-16
49, SZ-1655, L-580, L-5302, L
-5740, L-5402, L-5421, etc., SF-2935 manufactured by Dow Corning Toray Silicone Co., Ltd.
F, SF-2938F, SF-2940F, SF-29
45F, SF-2908, SRX-294A, SH-1
90, SH-192 and SH-193. (Co-catalyst) Examples of the co-catalyst include carbonate compounds such as ethylene carbonate and propylene carbonate, and phosphoric acid compounds such as phosphate esters and phosphite esters.

(Production Method) The polyurethane resin production method of the present invention is produced as follows.

The solution containing isocyanate is referred to as solution A,
The liquid containing polyol is used as liquid B, and the two liquids are mixed using an apparatus described later, and foaming and curing are performed.

Auxiliary agents such as a chain extender, a foaming agent, a catalyst and a foam stabilizer are appropriately mixed in advance with the solution A and / or the solution B as required.

The ratio of isocyanate groups to active hydrogen groups (N
(CO / OH equivalent ratio) is in the range of 0.7 to 5.0, preferably 0.9 to 3.0. NC
An O / OH equivalent ratio of 0.7 or more is preferable because urethane resin properties are excellent and 5.0 or less can keep brittleness low.

(Production Apparatus) In producing a polyurethane resin from the above raw materials, any apparatus can be used as long as it can be uniformly mixed. For example, a small mixer or a low-pressure or high-pressure foaming machine for producing general urethane foam can be used. In addition, heating can be performed if necessary prior to mixing.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Parts and% used in the examples below are based on weight unless otherwise specified.

[Measurement Method] (Method of Measuring Polyol Acid Value) Measurement was carried out in accordance with JIS-K1557. (Method for measuring polyol hydroxyl value) JIS-K1557
The measurement was performed according to the following. (Method of Measuring Polyol Viscosity) Measurement was performed at 60 ° C. according to JIS-K1557. (Measurement method of glycol water) The measurement was performed according to JIS-K1557. (Method of measuring water content of polyalkylene terephthalate) Pellets or flakes of polyalkylene terephthalate were heated at 100 ° C while flowing dry nitrogen, and the water content was measured by the Karl Fischer method. (Method for measuring molecular weight of polyalkylene terephthalate) 0.05 g of polyalkylene terephthalate was dissolved in 20 ml of degassed tetrahydrofuran, and a filtrate obtained by filtration using a 0.2 μm membrane filter was used as a sample. The medium was subjected to gel permeation chromatography using THF as a medium. The molecular weight was measured as a polystyrene standard. (Method of measuring water content of aromatic polyester polyol) JI
The measurement was performed according to S-K1557. (Method of measuring metal content of aromatic polyester polyol)
One gram of the polyol was collected in a conical beaker, 5 ml of concentrated sulfuric acid was added, and the mixture was heated and decomposed on a hot plate (or an electric heater), and hydrogen peroxide was added in the form of white sulfuric acid to decompose organic substances. 10 of the resulting degradable organisms
After adjusting the volume to 0 ml, the metal concentration was quantified by ICP emission spectroscopy.

(Evaluation prescription of polyurethane resin) In Examples and Comparative Examples, the following raw materials were used in the following ratios. <Components used for isocyanate side> Isocyanate: diphenylmethane diisocyanate (Mitsui Chemicals, Inc.)
A product obtained by mixing 53 parts by weight of Cosmonate PH (manufactured by Cosmonate Co., Ltd.) and 7 parts by weight of the polyols of the following Examples and Comparative Examples as a denaturing agent was used.

<Components Used for Resin Side> As the polyol, Mitsui Polyol EP-828 manufactured by Mitsui Chemicals, Inc.
60 parts by weight, Mitsui Chemicals Co., Ltd. Mitsui Polyol ED-
2840 parts by weight, 8 parts by weight of 1,4-butanediol manufactured by Tokyo Chemical Industry Co., Ltd. as a crosslinking agent, and water as a foaming agent
0.6 parts by weight, MINI manufactured by Activator Chemical Co., Ltd. as a catalyst
A mixture of 0.5 part by weight of CO and 1.0 part by weight of SF-2962 manufactured by Dow Corning Toray Silicone Co., Ltd. as a foam stabilizer was used.

<Production Method of Polyurethane Resin> The temperature of the isocyanate side and the resin side is previously adjusted to 40 ° C., and the mixture is stirred and mixed using a homomixer.
It was poured into a mold that had been adjusted to 0 ° C. After the injection, the mold was placed in an oven whose temperature was controlled at 40 ° C., and after 500 seconds, the mold was released, and physical properties were measured.

Example 1 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). Flakes, 1979 g, weight average molecular weight 55,700, number average molecular weight 18,600, water content 0.25% by mass) (hereinafter P
ET), triethylene glycol (manufactured by Mitsui Chemicals, Inc., 2020 g, water content 0.20% by mass)
(Hereinafter, referred to as TEG) and dehydrated at 50 ° C. under reduced pressure of −100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst.
The transesterification reaction was performed at 30 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (748 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was subjected to pressure filtration using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform aromatic polyester polyol (3252 g). The calculated aromatic ester content was 43.6%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

Example 2 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). Flake 1712 g, weight average molecular weight 55700, number average molecular weight 18600, water content 0.25% by mass), tripropylene glycol (2289 manufactured by Tokyo Chemical Industry Co., Ltd.)
g, a water content of 0.27% by mass) (hereinafter referred to as TPG), and dewatered at 50 ° C. under a reduced pressure of −100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst, and transesterification was performed at 230 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. The reaction was performed. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (821 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was filtered under pressure using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform aromatic polyester polyol (3179 g). The calculated aromatic ester content was 37.0%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

Example 3 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). Flakes 1979 g, weight average molecular weight 55700, number average molecular weight 18600, water content 0.25% by mass), triethylene glycol (772 g, Mitsui Chemicals, Inc., water content 0.20% by mass), hydroxyl value 280 Polypropylene glycol (Diol-400 manufactured by Mitsui Chemicals, Inc.)
1819 g, water content 0.2% by mass or less)
(Referred to as -400) and dehydrated at 50 ° C under a reduced pressure of -100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst, and the temperature was increased to 230 ° C.
For 1 hour in a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (549 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was subjected to pressure filtration using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform aromatic polyester polyol (3651 g). The calculated aromatic ester content was 28.1%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

Example 4 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). 1326 g of flakes, weight average molecular weight 55,700, number average molecular weight 18,600, water content 0.25 mass%), tripropylene glycol (940, manufactured by Tokyo Chemical Industry Co., Ltd.)
g, water content 0.27% by mass or less), hydroxyl value 280
Polyethylene glycol (PEG-400, manufactured by Tokyo Chemical Industry Co., Ltd., 1733 g, water content: 0.25% by mass) (hereinafter, referred to as Peg400), and -10
Dehydration was performed at 50 ° C. under a reduced pressure of 0 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst, and transesterification was performed at 230 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. The reaction was performed. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (542 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was filtered under pressure using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform polyester polyol (3658 g). The calculated aromatic ester content was 26.4%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Reactivity, density, tensile strength,
The rebound resilience showed good results.

Example 5 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). 1057 g of flakes, a weight average molecular weight of 55,700, a number average molecular weight of 18,600, a water content of 0.25 mass%, and a polypropylene glycol having a hydroxyl value of 280 (Diol-400)
2943g, water content 0.16, manufactured by Mitsui Chemicals, Inc.
% By mass) and dehydrated at 50 ° C. under a reduced pressure of −100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst.
The transesterification reaction was performed under a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid. Subsequently, while maintaining the temperature at 230 ° C., the inside of the reaction vessel was −50 to −10.
The pressure was reduced to 0 kPa, and a distillate (346 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C. and distilled water was added for 5 hours.
0 g was added and the reaction was carried out at 100 ° C. for 1 hour. Thereafter, the temperature was increased to -100 kPa at 120 ° C., the pressure was reduced, and dehydration was performed. Thereafter, the mixture was subjected to pressure filtration using a filter having a hole diameter of 4 μm and nitrogen at 3 MPa, whereby a pale yellow uniform aromatic polyester polyol (3
651 g). The calculated aromatic ester content is 1
9.9%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

(Example 6) Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). 753 g, weight average molecular weight 55,700, number average molecular weight 18,600, water content 0.25 mass%), diethylene glycol (348 g, water content 0.17 mass%, manufactured by Mitsui Chemicals, Inc.) (hereinafter referred to as DEG) , A polypropylene glycol having a hydroxyl value of 112 (Diol-100)
0 Mitsui Chemicals Co., Ltd. 2899 g, water content 0.15
% By mass) (hereinafter referred to as D1000).
Dehydration was performed at 50 ° C. under a reduced pressure of 00 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate was used as a catalyst (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.).
Was added, and a transesterification reaction was performed at 230 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (289 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was subjected to pressure filtration using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform aromatic polyester polyol (3651 g). The calculated aromatic ester content was 14.0%. The obtained aromatic polyester polyol was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

Example 7 Nitrogen was passed through a 5-liter four-necked round-bottomed flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). 2346 g of flakes, a weight average molecular weight of 55,700, a number average molecular weight of 18,600, and a water content of 0.25% by mass), and diethylene glycol (1654 g, manufactured by Mitsui Chemicals, Inc .; a water content of 0.2% by mass or less) were charged. Dehydration was performed at 50 ° C. under a reduced pressure of 100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst.
The transesterification reaction was carried out at 1 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid.

Subsequently, the pressure inside the reaction vessel was reduced to -50 to -100 kPa while maintaining the temperature at 230 ° C., and a distillate (952 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. The reaction mixture was cooled to 80 ° C., 50 g of distilled water was added, and the reaction was performed at 100 ° C. for 1 hour. Thereafter, at −120 ° C., −100
The temperature was increased to kPa, the pressure was reduced, and dehydration was performed. Then 4μ
The mixture was subjected to pressure filtration using nitrogen of 3 MPa using a filter having a hole diameter of m to obtain a pale yellow and uniform aromatic polyester polyol (3048 g). The obtained aromatic polyester polyol having a calculated aromatic ester content of 52.9% was evaluated as a urethane resin. The results are shown in Table 1. Good results were obtained for reactivity, density, tensile strength and rebound resilience.

[0047]

[Table 1]

Comparative Example 1 Polypropylene glycol having a hydroxyl value of 56 (Diol-2000, manufactured by Mitsui Chemicals, Inc., 2899 g, water content 0.15% by mass) (hereinafter referred to as D
-2000) to produce a urethane resin for evaluation. The results are shown in Table 2.

Comparative Example 2 To produce polypropylene glycol having a hydroxyl value of 56, a so-called double metal cyanation complex catalyst (DMC catalyst) comprising zinc cobalt cyanide, zinc chloride, water and dimethoxyethanol was used. Polypropylene glycol having a low all content (hereinafter referred to as low monol PPG) was synthesized, and a urethane resin was produced and evaluated. The results are shown in Table 2.

(Comparative Example 3) Nitrogen was passed through a 5-liter four-necked round bottom flask equipped with a stirrer, a distillation column, and a thermometer, dried sufficiently, and then recycled polyethylene terephthalate (Yono PET Bottle Recycle Co., Ltd.). 2490 g flakes, weight average molecular weight 55700, number average molecular weight 18600, water content 0.3 mass%), 1,4-butanediol (1509 g, Wako Pure Chemical Industries, Ltd., water content 0.2 mass% or less) And dehydrated at 50 ° C. under reduced pressure of −100 kPa. The pressure was returned to normal pressure while flowing nitrogen, and tetra-n-butoxytitanate (0.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst.
The transesterification reaction was carried out at 1 ° C. for 1 hour under a nitrogen atmosphere at normal pressure. At this point, the polyethylene terephthalate flakes had completely disappeared and became a uniform pale yellow liquid. Subsequently, while maintaining the temperature at 230 ° C.,
The pressure was reduced to -100 kPa, and a distillate (804 g) containing ethylene glycol by-produced from polyethylene terephthalate was distilled off. When the reaction mixture was cooled to 80 ° C., the reaction product became white and solidified, making subsequent evaluation impossible.

Comparative Example 4 Monomethyl terephthalate was added to the aromatic polyester polyol used in Example 1 to adjust the acid value to 0.55 mgKOH / g. Table 2 shows the results.

Comparative Example 5 An experiment was conducted in the same manner as in Example 1 except that antimony acetate was added to the aromatic polyester polyol used in Example 1 to adjust the metal content to 150 μg / g. Table 2 shows the results.

[0053]

[Table 2]

[0054]

The present invention provides a novel aromatic polyester polyol. This novel aromatic polyol can be obtained by transesterifying a polyalkylene phthalate resin with a glycol, and uses recovered and regenerated polyalkylene terephthalate and waste polyalkylene terephthalate generated in the manufacturing and processing steps. Therefore, it is effective for resource saving and waste reduction. Also, by producing a polyurethane using this novel aromatic polyester polyol, it is possible to produce a polyurethane resin having high strength and low rebound resilience, a resin suitable for applications requiring cushioning properties, Elastomers, foams and fine foams can be supplied. Further, the aromatic polyester polyol of the present invention does not need to be neutralized again with a base or the like, since the acid value can be lowered during the production. Since an expensive base component is not required and a neutralization step is not required, both the apparatus and the operation are simple.

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Claims (6)

[Claims] 1. An aromatic ester polyol obtainable by reacting a polyalkylene phthalate resin with glycol, comprising: 1) a hydroxyl value of 20 to 100 mg KOH / g, and 2) an acid value of 0.4 mg KOH / g or less. 3) a polyurethane having a metal content of 100 μg / g or less, 4) a content of COO—C ₆ H ₄ —COO units in the aromatic polyester polyol of 2% by mass or more and 65% by mass or less. Aromatic ester polyol for resin. 2. The viscosity measured at 60 ° C. is 2
The aromatic polyester polyol according to claim 1, wherein the aromatic polyester polyol is in a range of from 00 mPa · s to 50,000 mPa · s. 3. The method according to claim 1, wherein the glycol is obtained using a glycol having a water content of 0.3% by mass or less.
The aromatic polyester polyol according to any one of the above. 4. A weight average molecular weight of 20,000 to 80.
000 and a number average molecular weight of 8,000 to 3
The aromatic polyester polyol according to any one of claims 1 to 2, wherein the aromatic polyester polyol is obtained using a polyalkylene phthalate having a water content of 0.5 mass% or less in a range of 0000. 5. The method for producing an aromatic polyester polyol from a polyalkylene phthalate and a glycol, wherein the azeotropic dehydration is performed using a solvent azeotropic with water in the presence of a glycol. 3. The method for producing an aromatic polyester polyol according to item 1. 6. A polyurethane resin obtained by reacting the aromatic polyester polyol according to claim 1 with a polyisocyanate.